Correction: This story was updated to remove an attorney's claim regarding fee agreements involved in the case.

A Philadelphia attorney is facing a lengthy sanction for knowingly misrepresenting his status as the attorney for the father of a 12-year-old boy who was fatally shot by Philadelphia police.

On Monday, attorney J. Conor Corcoran agreed to an 18-month suspension, after he filed a civil lawsuit against the Philadelphia Police Department over the fatal shooting, despite not being retained by the father as counsel, and then later attempted to have the father declared mentally incompetent.